Safety mechanism for fuel burning devices



SAFETY MECHANISM FOR FUEL BURNING DEVICES Filed Juiy 10, 1924 3 Sheets-Sheet 1 April 19, 1932. w. w. WILLIAMS SAFETY MECHANISM FOR FUEL BURNING DEVICES 3 Sheets-Sheet 2 Filed July 10, 1924 April 19, 1932. w. w. WILLIAMS SAFETY MECHANISM FOR FUEL BURNING DEVTCES Filed July 10, 1924 3 Sheets-Sheet 3 the secondary circuit adapted to' open upon any break in either the secondary or primary.

{Patented Apr. 19, 1932 WALTER W. WILLIAMS, BLOOMINGTON,

ILLINOIS, ASSIGNOB TO WILLIAMS OIL-O- MATIC HEATING CORPORATION, OF .BLOOMINGTON, ILLINOIS, A CORPORATION OF ILLINOIS sarnrx nncrmnisu' non: rum; ammo mwrcns' l ipllcationflled m 10,192; Serial 110. 725,139.

My invention 'relat'esto fuel burningldevices andmore anism therefor.

The object of. my invention is in the pro vision of a safety control mechanism for fuel burners of the so-called domestic type.-

Another object of my invention is in the provision of a thermal safety control mech-" i anism for domesticfuel burners, sald control mechanism including switch mechanism in circuit. 7

Yet another object of my invention is in the provision of a safety control mechanism of the thermal type adapted to open the electrical circuit upon a failure of initial ignition or upon a cessation of combustion conditions during the operation of the burner.

Still another object of my invention is in the provision of a simple magnet switch located in the secondary circuit of a domestic fuel burner and adapted to be released upon any break in said circuit, thereby stopping the: operation of the burner.

A further object of my invention is in the provision of a simple magnet switch located in the' secondary electrical circuit of a domestic fuel burner and adapted upon any break in the electrical circuit to be released and thru appropriate electrical connections stop the operation of the burner.

A still further object of my invention'is in the provision of a magnet switch located in the electrical circuit and adapted, upon any break in the electrical circuit, to be released,

and thru appropriate mechanical, means, stopping the operation of the burner.

Another object of my invention is in the provision of means, in connection with the safety mechanism, for opening the electrical circuit to the house thermostat upon operation of the safety mechanism.

Other objects of my invention will appear in the following specification and claims taken in connection with the annexed drawings in which Fig. 1 shows a perspective of a domestic fuel burning device and its association with a formal boiler member including, also, the

particularly 'toa safety mech relative positioning of the control means .therefo'r'. a

Fig. 2 is :1 dia am showing the control mechanism, inclu 'ng the electrical circuit for/the burnen,

' Fig. 3 ,is'a-n enlar ed detail of the atomizing chamber in the uel burning device; and,

}.' -'F ig.-4 is a diagram showingof the control mechanism including the mechanical Fig; 5 is an enlarged detail of the switch 45a, showing the lever 38 in vertical section.

7 Referring to the drawings, I have shown my specific control mechanism in connection with a fuel burner of the so-called domestic type, said burner having formed the basis for a number of copending applications, including #683,266 filed December 28, 1923, and #578,618 filed July 31, 1922, which application later became Patent-N0. 1,711,436 dated April 30, 1929.

I do not limit the application of my control mechanism to this particular type of burner, inasmuch as it might also be used upon" any of the conventional types of fuel burners with merely minor changes therein.

Although described in detail in other copending applications, I desire at this time to descfribebriefly my fuel burning device.

The main operating portions include a conventional electric motor 10 having an extended axis upon which are mounted the operating portions of the burner, these portion's, including atomizing chamber 11, hav-. ing mounted therein in an eccentric manner, which respect to the outer housing, a rotor 12, said rotor containing, in a slidable manner, therein, vanes 13. A pump 14 of any conventional type is adapted to deliver fuel from'atank 15 through pipes 16 and 17 to a strainer member 18 where it is metered by a suitable pump member 19 into the before described atomizing chamber 11, where mufller, 20 provides means whereby air is taken into either the fuel inlet to the atomizing chamber or directly into said atomizing chamber. After atomization of the fuel mixture within the chamber 11, said mixture is delivered through an appropriate tube 21 to adischa-rge'nozzle 22 located just within a formal combustion chamber 23. Means for providing a forced draft to the combustion chamber is disclosed in a fan member 24 rotated by the main axis of the power element 10, the blast from said fan 24 being delivered through the blast housing 25. A means for deflecting the air blast from 'the fan 24 at the discharge point of the fuel mixture is accomplished by the blades 26 located in the discharge end of the burner and surrounding the dischargenozzle.

In Fig. 1, a return pipe 27 is shown to the main fuel container 15, said return means being utilized in order to permit an excess delivery of fuel to be compensated'for.

The present burner utilizes as an ignition means a temporary gas and electric pilot light, said pilot light operating only for a short time after the commencement of operation of the burner.

Mechanism included in my ignition means is as follows:

A diaphragm member 28 has connection,

through the pipe 29 with the atomizing chamber before described. A

An inlet valve 30 is controlled by the movement of said. diaphragm 28, the movement of which is naturally controlled by the rise and fall of pressure within the atomizing chamber. In other words, upon the commencement of operation of the burner, pressure will be raised within the atomizing chamber and transmitted simultaneously to the diaphragm 28 which will rise, or rather, be

extended and, hence, raise the fuel inlet valve to permit the passage of fuel to the device.

My ignition mechanism is operatively connected with this diaphragm mechanism and is operated thereby. This ignition mechamsm includes a formal dash pot 31, suitably supported at one side of the diaphragm casmg 32. A gas valve 33 is supported upon the opposite side. This gas valve 33 has an inlet member 34 from the source of supply and an outlet 35 leading to a point adjacent the discharge nozzle 22. The stem 36 is adapted to operate the gas valve 33. A proecting lug 3.7 is connected to the diaphragm 28 and is adapted to abut the under side of a lever 38 having operative connection with both the dash pot 31 and gas valve 33. This lever 38 is pivoted at 39 and has one of its ends slidably related at 40 with the projecting portion 41 of the dash pot. The oppos te end of the lever 38 has a pivoted port1on42 supported thereon in a manner. to engage t he projecting stem 36 of the gas valve. spring member 43 normally holds the lever m the positionshown in Fig. 2.

Briefly, describing the operation of this temporary ignition mechanism, it might be said that, upon a commencement of opera tion of the burner, pressure is transmitted from the atomizing chamber to the diaphragm 28 which is thereby raised, with the result that movement will be transmitted to the lever 38, with a consequent downward movement of the end 42 thereof. This downward movement of the end 42 will be resisted by the action of the dash pot 31, said downward movement, however, permitting the opening of the gas valve 33 due to the pressure exerted against the stem 36. This lever mechanism is fashioned in a manner to release the gas valve when the lever has attained an'elevated position due to the full extension of the diaphragm 28. The above is accomplished by the snapping of the member 42 off of the projecting end of the stem 36, hence," permitting the closing of the gas Valve even though the lever is in its raised position. We may see from the above the movement of the gas valve whereby, for a temporary period, gas is permitted to flow to apoint adjacent the discharge end of the burner. A spark mechanism is provided for igniting this gas, said spark mechanism including a conventional spark coil 44 that is energized upon the commencement of operation of'the burner. Means for controlling the time of operation of this spark coil is provided in the electrical connection. shown at 45 upon the mechanical ignition means above described. A knife switch 45a has frictional contact with the lever 38 in such manner that circuit to the spark coil is completed s long as the lever slides in this knife switch\v Wire 46 is shown connecting the knife switch and the spark coil, and a second wire 47 from the spark coil is grounded on the motor at 48. Another wire 49 is shown 7 leading to a formal electrode 50 disposed adj acent the discharge nozzle of the burner and in a position to ignite the. gas flame that issues from the gas pilot simultaneously with the energizing of the electrode. The above description is thought sufficient to show the cooperation of the gas and electric ignition mechanism, as well as, the operation of the mechanical means for energizing and operformal construction-and is adapted to operate a magnetic relay, generally described at R, through a secondary circuit formed by shunting the primary of transformer X across the main motor circuit.

With the above construction, operation of the housethermostat would make and break a high voltage circuit through the magnetic relay to the motor of the fuel burner.

The fuel burner, or rather, the motor thereof utilizes, of course, a high voltage current and the wire in this high voltage circuit has been marked 110, inasmuch as this current is usually 110 volts.

Details of the magnetic relay are as follows:

An armature 52 is pivoted at 53 and is adapted to oscillate between opposed magnetic coils 54 and 55 respectively. The movement of the armature 52 is adapted to make or break the main motor, or 110 volt, circuit atthe contact point 56. A second switch controlling a secondary current to the magnetic coils is disposed above the armature 52 and is described as 57, this switch is of the so-called spring type and has its movements controlled by the movement of the armature.

The above description is thought clearly descriptive of the fuel'burner and means for normally controlling and igniting same. However, at times, due to some unforseen happening, there may be either a failure of initial ignition, or a cessation of combustion conditions during the operation of the device, with the result that the fuel, or. rather, mixture thereof will be discharged into the combustion chamber and accumulate therein in a dangerous manner.

The art discloses "various safety mechanism for controlling this accumulation of fuel, and the present application is directed to a specific type of such control means. As said before, a formal transformer X is utilized for the purpose of'providing a secondary circuit including a house thermostat to control the operation of a main relay adapted to start or stop the burner; In the present instance, my safety control mechanism is intimately connected with this secondary circuit and includes the following mechanism:

A magnet 58 is adapted to attract at all times a contacter 59, said contacter, when released, being thrown to an opposed position by means of the spring member 60. The contacter 59 forms a part of a spring switch 61 similar to the before mentioned switch 57, said switch 61 being similarly located in the secondary electrical circuit formed by the.

transformer and controlling the circuit to the magnetic coils.

. Disposed in a position with relation to the combustion chamber to be sensitive to the changes in temperature therein, is an air chamber 63,'said air chamber having a connecting tube 64 leading to a formal mercury switch generally described as 65. This mercury switch 65 is made up of a glassU tube 66, said tube having a considerable amount of mercury 67 therein. An electrode 68 is shown in one of the arms of the U tube and adapted under some conditions to make contact with the mercury and to complete an electrical circuit through a second contact portion 69. The tube 64 connecting with the chamber 63 has an operative connection with the upper end of the arm of the U tube that does not have theelectrode 68 located therein. Electrical connections from the point 69 and the electrode 68 are shown as 5050, said electrical connections leading one to the transformer and the other to the magnet 58 before described.

Another set of electrical connections, also, in the safety control electrical circuit are shown at 7 57 5, these wires bringing into the control circuit the knife switch 45a in a manner to make or break the circuit through said wires 757 5. Tracing the wires 75-75, will find that they are connected to the wires 5050 respectively.

Perhaps before describing the operation of the safety control mechanism it might be well coil 54 and similarly a tracing of the off wire will find that it leads to the magnet coil 55, these coils being spoken of commonly as the on and off coils respectively. The common wire naturally forms one side of the electrical circuit depending upon whether the thermostat is moved to energize the on coil or off coil.

As said before, included in this secondary circuit is also the magnet 58 making up the magnet switch which includes the spring switch 61 and tensioned contact portion 59. Also, in this secondary circuit and adapted to control same is the generally described mercury switch 65, sensitive to combustion conditions, and the electrical circuit 75-75 controlled by the mechanically operating lever 38 which is operated by the diaphragm 28, sensitive to pressure conditions within the atomizing chamber as formerly described. The magnetswitch 58 is energized at all times by a branch electrical circuit from the transformer and will only be released by a break in said electrical circuit.

Describing the operation of my safety controlled mechanism, it may be said upon commencement of operation of the burner. the gas and spark ignition mechanism will be energized simultaneously with the operation of the burner and normally the resultwill be an ignition of the discharged fuel and a bustion chamber. The electricalcircuits affected in the above operation are the energizing due to the action of the thermostat of the on magnetic coil and, hence, movement of the relay to close the contact 56 and, hence, complete the 110 volt, or'high voltage circuit to the electric motor with consequent operation thereof. .The circuit 7 575 temporarily,

upon the commencement of the operation of the burner, is closed due to the retarded upward movement of the lever 38. It may be seen at this time that temporarily, upon the commencement of operation of the burner, the electrical circuit through the wires 50-5O is not made. inasmuch as the mercury in the U tube 66 does not touch the electrode 68. However, the completing of the circuit through the wires 7 5-75 maintains the magnet-in an energized positionand thereby maintains in a closed position the secondary electrical circuit.

Inasmuch as there will be an opening of the electrical circuit through the wires 7575 after a. determined time by the movement of the lever 38 from contact with the knife switch 45a, in order to maintain the magnet 58 energized at all times, some other means must be thrown into operation to complete the circuit to the magnet prior to the break ing of the circuit 75-75. This is accomplished in the following manner:

Under normal conditions, the rise in temperature in the combustion chamber after ignition of the fuel mixture will result in the expansion'of the air due to theheating of the bulb 63 resulting in pressure being transmitted through the tube 64, with the result that the mercury will rise upon the opposed side of the U tube and make contact with the electrode 68 thereby completing the circuit through the wires 50, which will also be in circuitwith the magnet 58. Under these conditions, and if the mercury switch has operated prior to the breaking of the circuit 7 5-7 5 due to the action of the lever 38, the

-magnet 58 will still remainenergized. It

may be seen from the above that the action of the magnet switch is controlled by both tain time is necessary for the heatingof the mercury switch through the connected elements. v

The normal operation of the device, relative to the safety mechanism has been given, butupon a commencement of operation of the burner and a failure of initial ignition, there will be no transmission of pressure, or, ex-

pansion of the air in bulb 63, to the mercury switch and, hence, no making of the electrical circuit therein, with the result that the pres sure raised in the atomizing chamber will operate the diaphragm 28, raise the lever 38, and eventually break the electrical connection in the circuit Z5 with the result that the electrical circuit through'the magnet 58 will be broken, thereby de-energizing same and permitting the coil spring 60 to break contact with the magnet and, at the same time, throw the spring switch 61. This movement of the spring switch energizes the opposed magnetic coil 55, or rather, the off coil and, hence, the attraction of the armature 52 in that direction breaks the main electrical circuit tothe motor. Similarly, upon a cessation of combustion conditions during operation. of the device, when the temperature is lowered in the combustion chamber, the mercury will recede and break contact with the electrode 68 whereupon, the circuit, including the magnet 58, will be broken, hence, a de-energizing of the magnet, with the consequent action of the coil spring 61 to break, not only the contact with the magnet, but also throw the to throw the switch 61.. Hence, the present safety device is adapted to control the operation of the burner, not only under the conditions above described, but also in case of a failure in the making of a contact,or rather, a faulty making of a contact and thereby controlling the operation of theburner under any and all conditions that might result in dangerous consequences, such as the accumulation of fuel, or a continuing fire with no means of interruption, due to faulty contacts in the control circuit. 7

It is, of course, obvious that a break in any, or rather, either of the electrical circuits would result in the release of the magnet switch to immediately stop the burner.

In Fig. 4 of the drawings I have disclosed a modification of my safety control mechanism. This modification relates to a mechanical means substituted for the before described magnetic switch 58 adapted to actuate the armature in the relay to open the 110 volt circuit, and at the sametime open the electrical circuitto the house thermostat thereby preventing any possibility of burning the thermostat out after operation of the safety mech- V anism.

Inasmuch as I have previously described in detail the operation of my safety mechanism, the objects desired to be obtained and the main portions included therein, I do not think it necessary to repeat such description and as a result, am only describing the structural device in the modified view.

The magnet 58 although shown in a somewhat modified manner in Fig. 4 is essentially the same and is connected in the electrical circuit by wires a and b, except that the switch 61 and spring tensioned, contact member 59 are no longer used as a means for energizing the off coil to throw the armature in the relay to an off position, and a mechanically operating device cooperating with said magnetic switch and armature is used to accomplish the same result. The contact arm 59 which was normally attracted by the magnet 58 has now taken the form of a contact lever 100, said contact lever being pivoted at 101 and having a hooked projection l02 'on its lower end. The hook projection 102 acts as a crank to throw the contact lever 100 to the dotted line position shown in'Fig. 4 under some circumstances. Operative connections between the contact lever 100 and the armature of the relay are shown as an arm 103 pivoted at 104:, said arm 103 having a weight member 105, adjustably mounted as at 106 thereon. The arm 103 has a. small hooked crank arm 107 forming a contact portion thereof, said crank 107 adapted to move the armature of the relay upon release of the lever 100 by the magnet 58 by abutting a projecting portion 108 on the'armature. This crank arm 107 is also fashioned in the hook mechanical safety cut- .the level-100. Upon release of the lever 100 the weight 105, through the crank 102, throws said lever to the dotted line position shown in Fig. 4 and simultaneously moves the arm 103 to the position shown in dotted lines in Fig. 4, with the result that the crank 107 has a similar movement thereby moving the armature to an off osition, or rather, opening the 110 volt'circuit. Likewise, movement through for any length of time after the operof the crank 107 to the left breaks contact with the contact point 110 and therefore .opens the electrical circuit including the house thermostat.

The advantage of breaking the electrical circuit, including the house thermostat, upon the operation of the safety mechanism, is to .prevent'any possibility of burning out 'the said thermostat due to current passing thereation of the safety device.

'WhatI claimis:

1. In a domestic fuel burner, in combination, a combustion chamber, a source of high voltage current, and electrically operated means adapted to be placed in circuit there- With for discharging an atomized fuel mixtureinto a zone of ignition, electrically actuated means for controlling the opening and closing the said circuit, asecondary circuit, a magnet normallyain said secondary circuit, automatic cut-ou't mechanism including a pressure operated mechanical means normally acting to open said secondary circuit, a mercury switch'sensitive to combustion conditions acting normally to prevent the opening of the magnet circuit but permitting the opening of said circuit in case of failure of initial ignition or upon cessation of combustion condition, and mechanical means associated with said magnet operated by the opening of the secondary circuit therethrough to mechanically operate the control means to open the high voltage circuit through the discharge means.

2. In a domestic fuel burner, in 'combination, a combustion chamber, an atomizing chamber, a source of high voltage current,

electrically operated means adapted to be placed in circuit therewith for dischar 'ng an atomized fuel mixture into a zone 0 ignition, electrically controlled means for opening and closing the-circuit therethrough; a secondary circult, an automatic cut-out mechanism including a. magnet normally in circuit with the secondary circuit, mechanism controlledby pressure in the atomizing chamber capable of opening the secondary circuitthrough the magnet after a determined tlme, and a thermal switch sensitive to combustion conditions adapted under normal combustion conditions to prevent the opening of the magnet circuit but in case of a failure of initial ignition-or cessation of combustion,

voltage circuit through conditions permitting the opening of the secondary circuit through the magnet, and mechanical means associated with the magnet operated by the opening of the seconda circult through said magnet to mechanically operate the control means to open the high the discharging means.

'3. In a domestic fuel burner, in combina-' tion, a combustion chamber, an electrically operated means for feeding an atomized fuel mixture to the combustion chamber, a source of high voltage current, electrically controlled means for opening and closingthe circuit through the feeding means, ignition means, a. secondary circuit, a safety cut-out mechanism ada ted to 'open and close the high voltage circuit through said feeding means including a magnet normally in circuit with the secondary circuit, mechanical means normally operating to open the circuit throu b said magnet and a thermal switch sensitlve to combustion conditions normally preventing the opening of said magnet circuit but permitting the opening of same upon I .an initial failure of ignition orupon a cessation of combustion conditions, and mei chanical means associated with the magnetically operated switch operated by the opening of the secondary circuit therethrough to v mechanically operate the control means to open the high voltage circuit through the 10 discharging means.

In testimony whereof, I have aifixed my slgnature. Y

WALTER W. WILLIAMS. 

